Acrylic Sealants
Conventional acrylic sealants are typically water-based (latex) compositions used in the low cost, low performance residential construction and home repair markets. Such sealants typically have poor flexibility and generally shrink due to water evaporation.
Latex acrylic emulsion sealants are generally based upon acrylic or methacrylic acid, their esters (typically methyl esters) or variations thereof. These prepolymer components are generally emulsified with other monomers, such as vinyl chloride. The emulsified prepolymer charge is then typically polymerized by free radical initiation, whereby the emulsion is maintained during and after polymerization. A wide variety of acrylic emulsions can be prepared by varying the type and blends of prepolymer components. The acrylic polymer emulsion is then formulated with other ingredients to produce the sealant. Such other ingredients typically include plasticizers which enhance flexibility, antifreeze additives to prevent freezing, and biocidal preservatives to prevent bacterial attack of the acrylic polymer.